Gripper apparatus on a ring spinning or ring twisting machine

ABSTRACT

The present invention relates to a gripper apparatus on a ring spinning or ring twisting machine for gripping empty and/or wound bobbin tubes using pegs mounted on a support beam extending along the machine and inserted into the interior space of the bobbin tubes, the bobbin tubes being gripped by pressing each bobbin tube and the peg inserted into it against each other. The pressing generally is effected using compressed air. According to the invention at each peg a cylindrical extension made of elastically bendable material is provided, which extension extends from the front end of the peg towards the tip thereof. 
     This arrangement yields the advantage that in case of faulty positioning of bobbins, tubes a head-on collision of the peg front end on the upper bobbin tube rim, with accordingly grave consequences, such as e.g. damage to the support beam or blowout of the compressed air, no longer can occur.

BACKGROUND OF THE INVENTION

The present invention relates to a new and improved gripper apparatus ona ring spinning or ring twisting machine for gripping empty and/orwound-on bobbin tubes using pegs arranged on a beam extending along themachine, which pegs can be inserted, by suitably moving the beam, intothe cylindrical interior spaces of the bobbin tubes, one peg beingprovided for each bobbin tube, and the pegs being tapered-off at theirfront end, which is inserted, in which arrangement the gripped bobbinsare held by mutually pressing a bobbin tube and a peg inserted into itsinterior space against each other.

In textile processing, bobbin tubes or bobbin packages in variousoperations are gripped automatically to be transported from one locationto another. As known e.g. from German Pat. No. 1,282,526 and from SwissPat. No. 500,303, particularly on ring spinning or ring twistingmachines in many cases a plurality of such bobbin tubes or of bobbinpackages, respectively, is to be gripped simultaneously. For thispurpose gripper devices, arranged on a beam, are inserted into thecylindric interior spaces of the bobbin tubes or of the bobbin packages,respectively, and by pressing these gripper devices and the bobbin tubeinside wall against each other, the bobbin tubes are gripped.

In this type of gripping of the bobbin tubes or the bobbin packagescases occur more or less frequently, in which one of the gripper devicesis not inserted correctly into the cylindrical interior space of thebobbin tube. This disadvantage is due, if a plurality of bobbin tubes isto be gripped simultaneously, to inaccurate positioning of one of thebobbin tubes, the probability of such inaccurate positioning increasingwith the number of bobbin tubes to be gripped simultaneously. For stillachieving correct insertion of the gripper device into a bobbin tubeeven in case the latter is somewhat inaccurately positioned, it is knownthat the front end of the gripper device, which is to be inserted intothe interior space of the bobbin tubes, is tapered-off conically.

This measure improves the conditions. However, the case can still occur,in which the point of the tapered-off front end of the gripper device,to be inserted into the bobbin tube, collides with the upper rim of thebobbin tube head-on. In this case, if pegs of hard material are used,the bobbin tube, the peg or even the beam for the gripper devices, orthe elements guiding and moving the beam respectively, can be damaged;on inflatable, bendable gripper devices cracks can develop, in suchmanner, that these gripper devices have to be replaced. Due to suchcracks furthermore the compressed air required for inflating the gripperdevices escapes, which can cause prolonged down time. Such damages thuscan be of serious nature.

SUMMARY OF THE INVENTION

Therefore, with the foregoing in mind it is a primary object of thepresent invention to provide an improved construction of gripperapparatus on a ring spinning or on a ring twisting machine which is notassociated with the aforementioned limitations and drawbacks of theprior art constructions.

Now in order to implement this and still further objects of theinvention, which will become more readily apparent as the descriptionproceeds, the gripper apparatus of the present development is manifestedby the features that each peg is provided with a cylindrical extensionmade from elastically bendable material, which extends from thetapered-off front end of the peg towards the front.

If, due to misaligned, faulty position of a bobbin, a head-on collisionof a front end of a peg on the upper bobbin tube rim would occur, in thearrangement according to the invention the front end of the extensioncollides with this bobbin tube rim. As the insertion movement proceeds,the extension and subsequently the peg slides along the bobbin tube rim,the bobbin tube being pushed to the side in such a manner that damagesare avoided. In this process the peg colliding with the bobbin tube rimeither is inserted into the bobbin tube, or continues to move outsidethe bobbin tube, along the bobbin tube.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those setforth above, will become apparent when consideration is given to thefollowing detailed description thereof. Such description makes referenceto the annexed drawings wherein:

FIG. 1 illustrates a first embodiment of the gripper apparatus accordingto the invention including an extension mounted on a support member,

FIG. 2 illustrates a second embodiment of the gripper apparatusaccording to the invention including an extension designed as a helicalspring,

FIG. 3 illustrates a third embodiment of the gripper apparatus accordingto the invention including an extension forming an integral piece ofmaterial with the peg wall; and

FIG. 4 illustrates a fourth embodiment of the gripper apparatusaccording to the invention including an extendable peg.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be understood that in order to simplify the illustration onlyenough of the construction of the gripper apparatus has been shown asneeded for those skilled in the art to readily understand the underlyingprinciples and concepts of the invention.

As already known, on ring spinning and ring twisting machines generallya large number of spindles are lined up along the machine length.Furthermore, a transporting belt and a support beam with gripperelements extend along the machine length. In this arrangement thesupport beam is used for transferring bobbin tubes from the transportingbelt to the spindles, or for transferring bobbin packages (wound bobbintubes) from the spindles to the transporting belt.

In FIG. 1 a support beam 11 of this type provided with a firstembodiment of the gripper apparatus according to the invention is shown.Using a screw 12 a peg 13 is mounted thereon. The peg is made of a hardmaterial, e.g. of a metal. In the longitudinal direction of the supportbeam 11, i.e. at right angles to the plane of the figure, a plurality ofsuch pegs 13 are arranged mutually spaced. Also in the longitudinaldirection of the support beam 11 a bendable hose 14 extends, which ismounted on the support beam 11 and on a support member 15. Into a bore,provided coaxially with the longitudinal axis 16 of the peg 13, anextension 17 is mounted. This extension 17 is made of bendable material.A bobbin tube, into which the peg 13 is inserted, is designated 18. Thepeg 13 is tapered-off conically at its front end which is inserted intothe bobbin tube 18.

For e.g. lifting bobbin tubes from the transporting belt (not shown) andto don them onto the spindles, the support beam 11 is moved towards thebobbin tubes located on the transporting belt in such a manner, thatinto the cylindrical interior space of each bobbin tube 18 a peg 13 eachis inserted. After the peg 13 is inserted to its maximum insertionposition, the air pressure inside the hose 14 is increased. Thus thehose 14 extends towards the peg 13 in such a manner, that the hose 14and the bobbin tube 18 are pressed against each other. In this mannerthe bobbin tube 18 is held by the peg 13 and the neighbouring hosesection. In the manner described, all bobbin tubes arranged on thetransporting belt of the spinning or twisting machine can be grippedsimultaneously and, using a corresponding movement of the support beam11, can be donned onto the spindles.

The case now may occur, as mentioned initially already, that not allbobbin tubes arranged on the transporting belt are accurately located intheir correct position. Owing to the conically tapered front end, whichis inserted, of the peg 13 disturbance-free insertion of the peg 13still is effected, even if the position of a bobbin tube deviates to acertain extent from the correct position. The case can occur, however,absence of the extension 17 being assumed, in which the frontmost partof the peg 13 collides exactly head-on with the upper rim of the bobbintube 18. In this manner the peg 13, the bobbin tube 18, but also thesupport beam 11 and its moving devices could be damaged.

Provision of the extension 17 implies that under the above mentionedcircumstances of faulty positioning the extension 17 can collide withthe upper bobbin tube rim. In this case the extension 17 is bent in itsfree portion as the suport beam 11 is lowered further. In this processthe bobbin tube 18 is pushed by the extension either into its correctposition or aside. Thus expensive damages are precluded.

In FIG. 2 a support beam 21 is shown, which supports a row of pegsextending at right angles of the plane of the figure, all pegs of therow being identical with the peg 23. The pegs are mounted using screws22. From the conically tapered section 26 again an extension 27 extendstowards the front. In this second embodiment of the gripper apparatusaccording to the invention the extension consists of a helical spring.The peg 23 furthermore is surrounded by a sleeve 28, the surface ofwhich is of relatively high holding friction. Using a surface of suchtype a bobbin tube pressed against the peg 23 is to be held moresecurely than as in contact with e.g. a smooth metal surface. In FIG. 3again a support beam 31, a peg 33 mounted using a screw 32, a hose 34and a support member 35 are shown. The peg 33, in this third embodimentof the gripper apparatus according to the invention, consists of a partmade of rigid material, which is surrounded by a sleeve 38 forming anintegral piece of material with an extension 37. An integral piece ofmaterial of this type presents the advantage of relatively simplemanufacture. The end of the extension 37 is rounded-off in such a mannerthat, in case the end of the extension 37 collides with the bobbin tuberim, the sliding off of the extension 37, and thus of the moving asideof the bobbin tube, are effected more reliably.

In the fourth embodiment of the gripper apparatus according to theinvention shown in FIG. 4 a support beam 41 is shown. On this beam 41pegs are mounted, each of which comprises, as the shown peg 43, a hollowspace 46 defined by a cylindrical sleeve. The peg 43 and the extension47 also in this arrangement form an integral piece of material. Thesupport beam 41 is provided with a chamber 44 extending over its wholelength. Each of the hollow spaces 46 of the pegs 43 arranged in thelongitudinal direction of the beam is connected via the duct 45 with thechamber 44. The front end of the extension 47 is defined by a surfacewhich is inclined with respect to the longitudinal axis of the extension47. Using this last mentioned embodiment again the sliding of theextension 47 is facilitated.

In order to grip a bobbin tube, or a plurality of such bobbin tubes,using the apparatus shown in FIG. 4, the pegs 43 are inserted into thecylindrical interior space of the bobbin tubes. Thereupon the airpressure in chamber 44 is increased in such a manner that also the airpressure in the hollow chamber or space 46 is increased. As the walls ofthe pegs 43 are elastic, they extend laterally to such an extent, thatthey contact the inside walls of the bobbin tubes into which the pegs 43are inserted, and that pegs and bobbin tubes are pressed against eachother. In this manner these bobbin tubes can be gripped and transported.

If a bobbin tube is arranged in a faulty position, the extension 47effects the action described with reference to the above mentionedembodiments. In this embodiment, however, the objective is not mainly toavoid damages to the support beam. A collision of the front end of thepeg 43 with the upper rim of a bobbin tube, in case of absence of anextension 47, primarily causes the formation of cracks in the peg 43.This causes additionally a blowout of the above atmospheric pressure inthe chamber 44, which causes, among other inconveniences, expensive downtime.

The extensions 17,27,37,47 are provided preferentially with thefollowing characteristics:

The length of the section extending from the front end of the pegtowards the front is at least equal to one tenth of the length of thepeg, at the most equal to half the length of the peg. The bounce-backhardness, or the elasticity respectively, of the extensions rangesbetween 25 and 90 degrees Shore. They are made preferentially fromrubber or thermoplastic material.

While there are shown and described present preferred embodiments of theinvention, it is to be distinctly understood that the invention is notlimited thereto, but may be otherwise variously embodied and practicedwithin the scope of the following claims. Accordingly,

What I claim is:
 1. A gripper apparatus for gripping bobbin tubes eachhaving an interior space and placed at a ring spinning or ring twistingmachine, said gripper apparatus comprising:a movable support beamextending along the machine and provided with pegs directed towards thebobbin tubes; each of said pegs having a tapered front end facing arelated one of said bobbin tubes and each peg being insertable into theinterior space of the related bobbin tube; and each said peg beingprovided with a substantially cylindrical extension formed by anelastically bendable material and extending forwardly from said taperedfront end of said peg.
 2. The gripper apparatus as defined in claim 1,wherein:each peg is provided with an axial bore which extends from saidtapered front end thereof; and said extension being of substantiallycircular cross-section and being mounted in said bore.
 3. The gripperapparatus as defined in claim 1, wherein:each peg comprises a metalcylinder; said metal cylinder being provided with a tapered frontsection and an axial bore extending therethrough; and said extensionbeing mounted in said bore.
 4. The gripper apparatus as defined in claim1, wherein:each peg comprises a wall made of an elastically bendablematerial; and said extension being formed integrally with said wall. 5.The gripper apparatus as defined in claim 1, wherein:said extensionpossesses a rounded front end.
 6. The gripper apparatus as defined inclaim 1, wherein:said extension comprises an end face which is inclinedwith respect to a longitudinal axis of said extension.
 7. The gripperapparatus as defined in claim 1, wherein:each said peg and saidextension have a respective predetermined length; and said predeterminedlength of said extension as measured from the front end of said peg isin the range of one-tenth to one-half of, said predetermined length ofsaid peg.
 8. The gripper apparatus as defined in claim 1, wherein:saidextension possesses a bounce-back hardness in the range of 25 to 90degrees Shore.
 9. The gripper apparatus as defined in claim 1,wherein:said extension comprises a helical spring.
 10. The gripperapparatus as defined in claim 1, wherein:said extension is made ofrubber.
 11. The gripper apparatus as defined in claim 1, wherein:saidextension is formed from a thermoplastic material.
 12. The gripperapparatus as defined in claim 1, wherein:said elastically bendable andforwardly extending extension is configured to preclude impact of thetapered front end of the peg with a rim portion of the bobbin tube.